It is recommended - certainly in the first few months of fish pond maintenance - to check your pond water for ammonia, nitrite and PH every week (or at any time that your fish look or behave differently) using a test kit. These are available from good aquatic retailers.
The ammonia and nitrite should both be below 0.5 ppm. NT Labs Pond Booster is an excellent choice for mainting these levels as well as phosphate.The pH should be between 6.5 – 8.5. Pond water should be part of your pond maintenance and should certainly be checked on a regular basis throughout the year.
The amount of food that your fish require is related to the temperature of the water. Fish should not be fed when the water temperature falls below 4ºC, when they will be dormant. During the autumn months it is advisable to feed a high energy, easily digestible food, such as the Nishikoi, Hikari or Tetra Wheatgerm Foods that will provide your fish with the reserves that they need to survive the winter. When the water temperature increases fish become more active and as a result they need more food, therefore fish require more food in summer than in winter such as a staple or growth food. Nishikoi, Hikari and Tetra, all offer these in their range of fish foods.
Do not be tempted to overfeed, and remove any uneaten food from the pond so that it does not pollute the water.
Having prepared your fish for the winter during autumn, this is also a time for preparing your pond for the cold months ahead. Cease feeding plants and remove them as they die back to prevent them from polluting the water by decomposing.
Where possible, prevent leaves from falling into the pond with the use of a pond cover net. Alternatively, remove any leaves that do fall in as otherwise these will decompose and pollute the water. Ensure that the pond is clean.
During the winter months of pond maintenance, be very careful not to feed your fish if they are likely to be dormant i.e. when the water temperature is below 4ºC as the food will decompose and pollute the water.
It is advisable with pond maintenance to ensure that the whole surface water of your pond does not become covered with ice for any prolonged period as fish may suffocate due to lack of oxygen. Decaying matter trapped under ice can also produce toxic gasses that can poison your fish. To prevent ice occurring over the whole of the pond surface a pond heater can be used. Alternatively, check your pond for ice, particularly during any prolonged cold spell and if ice does occur the best way to deal with it is to pour over some water to gently melt a patch. Never try hitting the ice to break it as this will result in shock waves that may kill your fish.
During spring, most ponds tend to suffer from an algae bloom. It is therefore advisable to pay particular attention to the condition of the water. The use of Blanket Weed removers and using Blanket Weed Treatments is recommended from early spring to early autumn, or you could fit an Electric Blanket Weed Remover.
As the water temperature increases and your fish become more active, begin feeding your fish with a good quality, easily digestible pond fish food.
Excess light, and / or an excess of certain nutrients (mainly nitrate and phosphate) can lead to excessive algae growth. Periodic partial water changes can reduce the levels of these nutrients in the water. It is also recommended that you try to keep the pond shaded from excess light and where necessary treat your pond against algae and green water, this is where installing a UV Steriliser is beneficial.